A semipro wrestler who became a policeman, a Trekkie who made more than 500 arrests, a giant of a man who was filled with humor and compassion.

Robert Parker was remembered as all these things yesterday as thousands of fellow police and family members paid their final respects to the slain detective.

“He never let anybody down,” said Deputy Inspector Vincent DiDonato, who held back tears as he eulogized “his brother by another mother.”

“Bobby had nothing but friendly feelings,” DiDonato said. “He was like the people motel – once you checked in with him and became his friend, you never checked out.”

Parker was mourned yesterday morning at the Christian Cultural Center church in Flatlands, Brooklyn, by a crowd that included his many friends from the 67th Precinct Detective Squad where he worked, police commissioner Raymond Kelly and Mayor Bloomberg.

“He was known as the heart and soul of the detective squad,” the Mayor said. “In Brooklyn, he was a favorite son, a king in the County of Kings.”

The 22-year veteran of the force died last Friday alongside his partner Patrick Rafferty, 39, when a suspect grabbed his gun and blasted them in the chest. Parker managed to use his dying breath to tell dispatchers where they could find a picture of the suspect, who was later captured.

“He was fulfilling his duty as a police officer up to his final moments,” Bloomberg said.

Like Rafferty, who was laid to rest on Wednesday, the 43-year-old Parker was remembered by thousands of officers from the NYPD and departments as far away as Toronto. They formed a blue wall that stood at attention while a motorcade headed by dozens of motorcycle cops led the funeral procession.

Parker was remembered for his colorful life, which include a period when he wrestled in a semipro league under the stage name “Bootsie Parker.”

That was before he went to John Jay College, studied criminal justice and became a cop in 1982.

Bloomberg said that the 6-foot-3, 250-pound Parker made 500 arrests. Kelly said he was such an imposing presence that other officers would be happy he was there to perform tough duties such as serving subpoenas on mob figures.

“He would ring the bell, the door would open and they would take the papers very politely,” he said.

DiDonato said Parker was a stationhouse cut-up known for his love of movies, television and giving his fellow officers good-natured ribbing.

When another detective bought a pastel jacket from the 1980s cop show “Miami Vice” off eBay and showed it around, the hulking Parker just had to try it on, even though it was for the much smaller Don Johnson.

“He misbehaved with integrity,” DiDonato said.

Parker was also a “Star Trek” fanatic who once pretended to do a “Vulcan mind-meld” on a murder suspect to get him to talk, the mayor said.

He was also remembered for his love of people. Jovial and gregarious, Parker could have retired from the force as second-grade detective, but he chose to continue working because he loved the interaction with people in the community.

DiDonato said that in the end, his love of people and his love of “Trek” became one.

“His favorite ‘Star Trek’ movie was ‘The Wrath of Khan,’ the one where Mr. Spock dies to save the ship,” DiDonato said. “It was so unbelievable that he went out like Mr. Spock. He [Spock] said ‘The needs of many outweigh the needs of the few.’ That was Bobby Parker.”

Parker, who was posthumously promoted to a detective first-grade was taken by motorcade to La Guardia Airport immediately after the funeral. His body was set to fly to North Carolina where it will be buried beside his mother, Ruby Lee Parker.

“He definitely was a gentle giant, a wonderful person,” said friend and fellow detective Peter Pliarte after the service. “He was one of the best.”